Tag: science & technology

Crowded places increase the risk of exposure to infectious respiratory droplets from infected individuals. Social distancing and avoiding crowds were key recommendations during the 2009 H1N1 pandemic to reduce transmission rates.

Influenza viruses can survive on hard surfaces like doorknobs and tables for several hours to days with infectivity typically lasting 2 to 8 hours under normal conditions. This survival time enables fomite transmission and makes surface disinfection important.

Staying home when sick with flu-like illness prevents spreading the virus to others in the community. This isolation should continue until fever is gone for 24 hours without fever-reducing medication not necessarily until the disease is completely cured.

WIMPs are Weakly Interacting Massive Particles, a hypothetical class of particles that are candidates for dark matter. They interact through gravity and the weak nuclear force but not through electromagnetic or strong nuclear forces, which explains why they don't emit or absorb light. 'Massive' doesn't just mean large - in physics, it means they have mass (as opposed to being massless like photons). The other options are incorrect expansions of the acronym.

Gravitational lensing occurs when a massive object (like a galaxy cluster) bends spacetime, causing light from distant objects to curve around it. The massive object acts as a lens, magnifying and distorting the light from background sources - galaxies or quasars behind it. This effect, predicted by Einstein's General Relativity, has nothing to do with Earth's gravity interrupting telescopes. It's a powerful tool for studying dark matter and distant galaxies. Options A, B, and D incorrectly focus on Earth's gravity rather than massive astronomical objects.

WMAP (Wilkinson Microwave Anisotropy Probe) was a NASA satellite (2001-2010) that measured the cosmic microwave background radiation across the full sky. These measurements revealed the universe's age (13.8 billion years), composition (dark energy, dark matter, ordinary matter), geometry (flat), and evolutionary history. It wasn't designed to detect comets or measure the Sun's temperature - those are completely different astronomical missions. Option D is wrong because WMAP had a very specific cosmology mission, not multiple purposes.

Just beyond the orbit of Neptune (the outermost planet) lies the Kuiper Belt - a region of icy bodies and dwarf planets like Pluto. Beyond the Kuiper Belt, at the outer edge of the Solar System, is the Oort Cloud - a spherical shell of icy objects that marks the boundary of the Sun's gravitational influence. Comets originate from both regions. While comets, dust, nebulae, and dark matter all exist in space, the specific structure immediately beyond the Solar System is the Kuiper Belt followed by the Oort Cloud. Nebulae are light-years away, and dark matter is distributed throughout the universe, not just beyond our Solar System.

The twin paradox demonstrates time dilation in special relativity: a twin traveling at high speed ages slower than their Earth-bound sibling. This occurs because the traveling twin experiences acceleration and deceleration, breaking the symmetry between the two reference frames. Options A and B describe scenarios unrelated to the actual paradox.

Orion is a constellation - a pattern of stars as seen from Earth - not a galaxy. Andromeda (M31), Sombrero (M104), and Milky Way are all galaxies. Galaxies contain billions of stars, while constellations are apparent star patterns that may include stars at vastly different distances.